Locking mechanism for switches



Feb. 3, 1931. w. s. MAYER LOCKING MECHANISM FOR SWITCHES Filed Sept. 8,1926 INVENTOR. MQZier S. We

ATTORNEYS.

Patented Feb. 3, 1931 v PATENT OFFICE WALTER S. OF PHILADELPHIA,PENNSYLVANIA LOCKING MECHANISM FOR SWITCHES Application mm September a,1926. Serial No. 134,171.

My invention is designed to provide improved means for preventing theaccidental or undesired movement or disengagement of-a movable member,such as the pivoted blade of an electric switch, from a fixed member,such as the base or brushes of such switch, but permitting readymovement or disengagement of such movable member by a pull or thrust onthe latching mechanism in the direction of desired movement 0 the switchblade.

It is well known that the magnetic effect of heavy current passingthrough a switch blade, and the weight of the blade itself when hung ininverted position, tends to disengage the blade from its brushes orwipes, and various latching mechanisms have been devised to overcomethis defect. In such mechanisms, the latching is usually 30 effected byspringing a movable tooth or jaw over a fixed tooth or jaw, andconsequently the planes of the engaging surfaces must be so disposedthat a sufficiently strong pull on the'blade will separate them or theblade must be moved inward toward its seat before it can be movedoutward from its seat, with resulting complexity of construction anddifliculty of operation.

In accordance with my invention, latching mechanism is providedcomprising complementary fasteners fulcrumed or pivoted on therespective fixed and movable members of the switch, and the fulcrumed orpivoted member carried by the switch blade is rocked not only to movethe latching tooth thereon out of latching position but to also move thelatching tooth on the fixed member of the switch out of latchingposition, so that unlatching is quickly effected with but slightmovement of either latching member. My improvements also permit the useof contacting surfaces on the latching members so inclined relatively toone another that a pull on the switch blade tends to tighten the hold ofthe latching members.

In the preferred embodiment of my invention, a pull ring is pivotallyconnected with the end of the switch blade and pro vided with aplurality of teeth spaced by a projecting nose and cooperating withtrig-- gers mounted on the switch base and elastically supported so thatthey give to permit the engagement of the teeth on the pull rin springinto latching position when the teet on the pull ring have assed theteeth on the triggers, and are roc ed by engagementof the nose on thepull ring when force is applied thereto to disengage the switch.

The characteristic features and advantages of my improved mechanism willmore fully appear from the following description and the accompanyingdrawing illustrating a preferred embodiment of the invention.

In the drawing, Fig. 1 is a top plan view of a disconnecting switchhavin my improved latching mechanism app ied there to; Fig. 2 is a sideelevation of the switch shown in Fig. 1 mounted on a base; Fig. 3 is atransverse sectional view taken on the line 3-3 of Fig. 2; Fig. 4: is adetached top plan view of the saddle for the base trigger; Fig. 5 is aside elevation of the saddle shown in Fig. 4:; Fig. 6 is a'detached topplan view of the base triggers; Fig. 7 is a side elevation of thetriggers shown in Fig. 6; Fig. 8 is a detached view of the pull ring andits connected triggers; Fig. 9 is a top plan view of the pull ring shownin Fig. 8; and Fig. 10 is a top plan view of a slightly modified form ofpull ring.

As illustrated in the drawing, my improved latching mechanism is appliedto a disconnecting switch comprising terminal blocks 1 and 2 providedwith the terminal posts 3 and 4 for the attachment of electricconductors, the terminal blocks being preferably mounted upon anon-conducting base 5, or upon pillar insulators or the like.

The block 1 has formed thereon the clevis 6 in which the switch blade 7is journalled by a bolt 8 havin thereon spring washers 9 and nuts 10. Srlng webs 11 are mounted on the block 2 an form wipes or jaws .betweenwhich the blade 7 may be entered to electrically connect the conductorsengaged with the binding posts 3 and 4. In accordance with my invention,the block 2 has mounted thereon a saddle 12 in which is journalled apintle 13 having fixed thereto the spaced triggers 14 recessed to formthe teeth 15 and I sheet having inclined to s 16. The teeth of thetriggers are norma 1y moved away from the wipes 11 by the action of acoiled spring 17 wound on the pintle 13, the movement of the triggerbeing limited by the engagement of cam surface or tail 18 of the triggerwith the saddle plate.

A pull ring 19 is preferably formed from metal sides containing theaperture 20, the sides being spaced by a filler 21 of slightly greaterthickness than the switch blade and leaving a space between the ends ofthe side members for the insertion of the end of the switch blade.

The pull ring is pivotally connected with the end of'the switch blade bya pintle 22, and the end of the filler 21 is so shaped as to providestops limiting the rocking of the pull ring on the blade. The forwardedges of the side membersof the pull ring are shaped to form teeth 23,23 which are spaced by projecting nose members 24: having inclinededges.

As illustrated in Fig. 10, the filler may be omitted from the pull ringand the metallic side pieces bent to form shoulders 19 providing a spacefor the insertion of the end of the switch blade.

The switch blade is thrown from the open to the closed position byengaging a rod or hook in the aperture 20. The rocking of the ring 19 islimited by the engagement of an abutment of the filler with the end ofthe switch blade and the thrust or pull on the pull ring moves the bladetoward the wipes 11. When the switch blade has partly entered betweenthe wipes 11, the teeth 23 enga e the inclined tops 16 of the triggers14 and orce them back against the action of the spring 17 so as topermit the teeth 23 to clear the teeth 15. The spring then restores theteeth 15 to their normal position in engagement with the teeth 23,thereby preventing the disengagement of the inclined engaging surfacesor the outward movement of the switch blade.

When it is desired to open the switch, a hook is inserted in theaperture 20 and a pull or thrust exerted on the member 19, which resultsin the rotation thereof upon its pivot, with consequent engagement ofthe nose members 24 with the inclined tops of the triggers 14, theretraction of the teeth 15 from the teeth 23 and the movement of theteeth 23 outwardly from the teeth 15, thereby disengaging the latchingsurfaces and permitting the opening of the switch. By making thesurfaces of the teeth 15 and 23 inclined relatively to one another, theseparation thereof by a pull or thrust directly upon the switch blademay be rendered impossible.

It will be understood that my invention is applicable not only to asingle throw switch as illustrated but also to a double throw switch bymerely placing a terminal block 2,

with its associated parts, on the opposite side of the terminal block 1in reverse position to that shown.

Having described my invention, I claim 1. The combination withrelatively fixed and movable members, of latching mechanism thereforcomprising complementary fulcrumed fasteners on the respective members,said fasteners being rockable in opposite directions and said fastenershaving inclined members adapted to coact to release and lock saidmovable member.

2. The combination with relatively fixed and movable members, oflatching mechanism therefor comprising a fulcrumed latch on each of saidmembers, and means for rocking said latches in opposite directionsincluding a pull member having an inclined nose.

3. The combination with relatively fixed and movable members, ofpivotally connected interlatching mechanism therefor comprising afulcrumed device on each of said members and each movable from theother, one of said devices being rocked by the rocking of the other ofsaid devices to release and lock said movable member.

4. The combination with relatively fixed and movable members, oflatching mechanism therefor comprising a pull member pivotally mountedon said movable member and provided with an engaging tooth and inclinednose a trigger elastically connected with said fixed member and having atooth and inclined top cooperating respectively with said tooth and nosefirst named said teeth and inclined top being offset from theirrespective pivots, and means limiting the rotation of said pull ring.

5. The combination with relatively fixed and movable members, oflatching mechanism therefor comprising a pull member pivotally connectedwith said movable member and having spaced teeth with a nose betweenthem and toothed members connected with said fixed members andcooperating with said teeth and nose.

6. A pair of complementai bers each mounted upon a evice. one of saiddevices being movable relatively to the other, said members havingaligned fulcrums, one of said members having a projection retracted inone direction from the line connecting said fulcrums and a projectionengaging and moving the other of said members upon the rocking thereofupon its fulcrum, and the other of said members having a projectionretracted by said engagement from said line in a direction opposite thedirection of said first named retraction.

7. The combination with a device having thereon a fulcrumed latchingmember forming a hook, of a second device having thereon a pivotedlatching member having a tooth complementary to said hook and retractedfrom latching position by movement of said latch memmember on its pivot,and a nose movable by said movement of said member against said hook andretracting it from latching position, one of said devices being movablerelatively to the other.

, 8. The combination with a device having thereon a latching memberhaving a tooth, of a second device having thereon a complementary memberhaving a tooth and a nose between whichsaid tooth first named ispositioned in engaging position, one of said devices being movablerelatively to the other.

9. The combination with a device having thereon a fulcrumed memberhaving a pair of inclined edges, of a second device having thereon acomplementary fulcrumed member containing a recess bounded on one sideby a tooth engaging one of said inclined edges and on the opposite sideby a nose engaging the other of said inclined edges, one of said devicesbeing movable relatively to the other.

10. The combination With a device having thereon a fulcrnmed memberforming a hook, of a second device havin thereon a pivoted member havinga pair 0 projections on one side of said pivot, said hook being engagedby and between said projections, one of said devices being movablerelatively to the other.

In testimony whereof I have hereunto set my name this 30th dav of Aug,1926.

WALTER S. MAYER.

